LessOnline
“A Festival of Writers Who Are Wrong on the Internet”
June 5 – 7, 2026 · Berkeley, CA
What Is LessOnline?
LessOnline is a festival celebrating truthseeking and blogging. It’s an opportunity to meet people you’ve only ever known by their LessWrong username or Substack handle.
The goal is to bring together a “mostly-online subculture of people trying to work together to figure out how to distinguish truth from falsehood using insights from probability theory, cognitive science, and AI.”
The weekend will be filled with talks, workshops, dance parties, and late-night conversations around the fireside.
This is the third year of LessOnline. Last year over 700 people attended, and we’re expecting roughly the same number this year.
Some Writings We Love
The sites below embody the virtues we are celebrating. Each author below has been offered a free ticket
Images of Yesteryear
LessOnline 2025
Voices from Past Expeditions
What attendees had to say
Fig. I — Like Moths to a Lightbulb
For Jorge Luis Borges, paradise was a library. At nearly 70 years of age, I’ve found my paradise at Lighthaven… I know of nowhere else on Earth where I can find so many interesting conversations in such a compact area.
What I’ll remember most from LessOnline is not the sessions, mine or others’, but the unending conversation among hundreds of people all over the grounds, which took place in parallel with the sessions and before and after them, from morning till night. It felt like a single conversational archipelago, the largest in which I’ve ever taken part, and the conference’s real point.
I had a great time at LessOnline. It was both a working trip and also a trip to an alternate universe, a road not taken, a vision of a different life where you get up and start the day in dialogue with Agnes Callard and Aristotle and in a strange combination of relaxed and frantically go from conversation to conversation on various topics, every hour passing doors of missed opportunity, gone forever.
Book Passage
Secure your place at the festival
Fig. II — The Printing PressAll-Access Ticket
Full access to LessOnline, Summer Camp, and Manifest. All meals included.
LessOnline Ticket
Three days of conversation, talks, debates, unconferences, and late-night arguments. 5 meals included.
Summer Camp Ticket
The week between LessOnline and Manifest: fire pit conversations that run too late, attendee-run sessions, unhurried socializing. Imagine the liminal space between conference talks but for a whole week.
Learn more about Summer CampManifest Ticket
A festival for prediction markets, forecasting, and spirited debates about the future. Friday evening through Sunday. 5 meals included.
Book a Room
Stay on campus at Lighthaven
Please do not book a stay for a period of time overlapping with an event that you do not have a ticket for. If you rent a room for a period for which you do not have a ticket, you will not be allowed to check in to your room and no refund will be issued.
Currently you can only purchase stays that last 9 days or more. That number will go down next week and will continue to go down most weeks until the start of LessOnline.
Frequently Asked
Questions & answers
Unfortunately there's about a 10 to 1 ratio of people to rooms, so most people will have to find other accommodations. See the Book a Room section above for more info.
